title: Diagnostic accuracy of the Cepheid GeneXpert vanA/vanB assay ver. 1.0 to detect the vanA and vanB vancomycin resistance genes in Enterococcus from perianal specimens.
abstract: Rapid detection of vancomycin-resistant enterococci (VRE) carriers could be useful to health care facilities to minimize transmission. To that end, we compared the performance of the Cepheid GeneXpert vanA/vanB assay with that of direct and broth-enriched culture methods for detection of VRE from perianal swabs. Enterococci were cultivated on Enterococcosel™ agar with 8 μg/mL vancomycin, Bile Esculin Azide Agar with 6 μg/mL vancomycin, and Bile Esculin Azide Enterococcosel Broth. Compared to the reference standard (combination of direct agar plating, broth-enriched culture, and clinical chart review), the sensitivity, specificity, positive predictive value, and negative predictive value of the vanA/vanB assay were 96.4%, 93.0%, 92.0%, and 96.9%, respectively (n=184). The 95% limit of detection was 100 colony-forming units (CFU)/mL for vanA and 114 CFU/mL for vanB. In summary, the GeneXpert vanA/vanB assay is a rapid and accurate method to identify vanA/vanB-colonized patients for VRE screening programs that use perianal swab specimens.
authors.affiliation: University of Arizona, Tucson, AZ 85724-5059, USA.
authors.forename: Erin S
authors.initials: ES
authors.lastname: Marner
authors.forename: Donna M
authors.initials: DM
authors.lastname: Wolk
authors.forename: Jeanne
authors.initials: J
authors.lastname: Carr
authors.forename: Carolyn
authors.initials: C
authors.lastname: Hewitt
authors.forename: Lorraine L
authors.initials: LL
authors.lastname: Dominguez
authors.forename: Thomas
authors.initials: T
authors.lastname: Kovacs
authors.forename: Desiree R
authors.initials: DR
authors.lastname: Johnson
authors.forename: Randall T
authors.initials: RT
authors.lastname: Hayden
mesh_terms: D001003:Anal Canal / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics*; D001431:Bacteriological Techniques / Q000379:methods*; D019729:Carbon-Oxygen Ligases / Q000235:genetics*; D018929:Cell Culture Techniques; D016983:Enterococcus / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; C079913:VanB protein, Enterococcus; D019729:Carbon-Oxygen Ligases